Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
Lithography processes involve transferring a pattern from a lithography mask or reticle to a material layer on a semiconductor device. In some lithography methods, a layer of photoresist is applied over the material layer to be patterned, and the layer of photoresist is exposed to energy, such as light, through or reflected from the lithography mask. The layer of photoresist is then developed and used as a mask to etch away portions of the material layer.
If defects reside on the lithography mask, the defects can be transferred to the material layer on the semiconductor device, resulting in undesired patterns in the material layer. The undesired patterns on the semiconductor device can result in poor device performance, shorts or opens, and decreased device yields, depending on the type, location, and severity of the defect.
Defect detection on lithography masks is performed manually and thus there is a risk of human error, resulting in some defects being overlooked or being incorrectly detected. Furthermore, manual defect detection is time-consuming.
What are needed in the art are improved methods of detecting and managing defects of lithography masks and semiconductor devices.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.